Conveyer for labeling machines and the like



July 18, 1939. G. w. VON HOFE El AL 2,166,776

CONVEYER FOR LABELING MACHINES AND THE LIKE Filed Feb. 10, 1938 3 Sheets-Sheet 1 INVENTORS I4: vo/v Hoff HAMMER fix wl'ew/wr ATTORNEYS.

1939- s. w. VON HOFE ETAL 2,166,776

CONVEYER FOR LABELING I\IIACHHI.'I"1ESv AND THE LIKE Filed Feb. 10, 1938 3 Sheets-Sheet 2 I I l l l l I l l I l I GEORGE. w /W95 i:

ATTORNEY 5.

July 18, w N HQFE ET AL 2,166,776

CONVEYER FOR LABELING MACHINES AND THE LIKE a a m mmm. 0 w w Ww m e a m I m 3 MN a A n m I' 4 1 0 Y 1 B, m o w f 1 3 m M i 3 zm wflwwm J m ma a 6 a? MM I t: N 5 7 6 aw w w I 1 v a 4 2 .(m 5 /1 7 w w .w 1 3 5 4 Patented July 18, 1939 CONVEYER FOR, LABELING MACHINES AND THE LIKE Application February 10, 1938, Serial No. 189,726

UNITED STATES PATENT OFFICE.

1 Claim.

The invention relates to but is not restricted to labeling machines and has for its object to provide novel and simple mechanism whereby articles, exemplified by articles to be labeled, are transported over a given or predetermined path and'efiiciently held or clamped in place during transport. The invention contemplates in addition the provision of novel means operating automatically in predetermined synchronism with associated mechanism whereby the holding or clamping means is periodically adjusted or shifted to an inoperative position to permit said articles to be readily placed upon and removed from the transporting mechanism. A further object of the invention 'is to provide a novel and simple registering or setting means for setting the articles in predetermined positions, exemplified by predetermined label receiving positions, during transport thereof by the transporting mechanism. Other more specific objects will appear from the description hereinafter and the features of novelty will be pointed out in the claim.

In the accompanying drawings, which illustrate an example of the invention without defining the limits thereof, Fig. 1 is an elevation, with intermediate parts broken away, of the novel mechanisms; Fig. l is a corresponding view and continuation of Fig. 1; Fig. 2 is a sectional elevation on an enlarged scale on the line 2-2 of Fig. 1; Fig. 3 is a fragmentary elevation, partly in section, of a novel setting or registering means which may form part of the mechanism, and Fig. 4 is a fragmentary plan view thereof.

For purposes of illustration and description, the novel mechanisms are shown in the drawings in a form adapted especially for embodiment in labeling machines and are correspondingly described in the specification. While the mechanisms in question are particularly adaptable to labeling machines, said mechanisms may be used with equal efiiciency in other types of machines, and it is accordingly to be understood that the selected illustrations and the associated description are not to be construed as limiting the range of utility of the improvements.

In its illustrated form, the machine comprises a suitable frame on which a movable or travelling support is mounted in any convenient manner for transporting articles over a given or predetermined path dependent upon the nature of the operations to be performed. An endless conveyer is so arranged that its one run constitutes the aforesaid movable or travelling support for the articles to be transported over the given or predetermined path traversed by said one run of said endless conveyer. The latter preferably consists of a plurality of supporting plates i i adapted to support the articles to be transported,

said plates ll being moved over the aforesaid given or predetermined path by a suitable actuating means. The given or predetermined path traversed by the plates H is preferably defined by a stationary member l2 suitably supported by the frame H] and along which said plates II are movable by the cooperating actuating means; the arrangement is such that the plates I! rest upon the stationary member l2 during travel lengthwise thereof and are accordingly supported by said member I 2 or otherwise maintained thereby in said given or predetermined path.

The actuating means whereby the plates l! are operated may consist of a sprocket chain l3, the one run of which preferably travels in a channel l4 extending lengthwise of the member l2 as shown. The sprocket chain I3 passes over and is actuated by sprocket wheels is rotatably mounted in any convenient manner on the frame ill, it being understood, if the sprocket chain It is replaced by an equivalent device, that properly co-operating actuating means will in such case be substituted for said sprocket wheels l5. To facilitate the operation and reduce friction to a minimum the sprocket chain it is of the roller type and accordingly includes rollers I6 rotatably mounted on the pivot pins whereby the links of said sprocket chain l3 are pivotally connected with each other; sprocket chains of the roller type are well known and accordingly no detail illustration of this feature of the chain [3 is required. The supporting plates l I may be arranged for movement with and by the sprocket chain l3 in any convenient manner, as. shown for instance in Fig. 2 by suitably mounting each plate ll upon one of the links which together constitute the chain iii. The parts are arranged and dimensioned so that, as illustrated in Fig. 2, the plates II will movably rest upon the stationary member 12 upon opposite sides of the channel [4 thereof, as the one run of the chain 13 or its equivalent travels lengthwise of said channel M in the operation of the mechanism. The plates l l accordingly are positively supported in travelling over the given or predetermined path, and sagging thereof under dead weight and the weight of the supported articles isprevented; the

indicated arrangement has an additional purpose which will be referred to more clearly hereinafter.

The mechanism further includes releasable clamping means whereby the articles are clamped in place on the movable or travelling support, and means whereby the clamping means is maintained in operative relation to said articles during movement thereof by said movable or travelling support.

The releasable clamping means include clamping devices comprising clamping plates l1 arranged for co-operation with suitable releasing mechanism in a manner and for the purpose to be more clearly pointed out hereinafter; in the form shown in the drawings the clamping plates I! are accordingly provided along opposite longitudinal edges with ribs Il for the above purpose. The clamping plates H are mounted in any suitable manner to develop a clamping action on the articles during transport thereof by said movable or travelling support, and as illustrated may be yieldingly supported to effect this result. As shown in Fig. 2, each clamping plate I! is provided with spaced parallel rods l8 slidably combined with a guide plate l9 and carrying springs 20 whereby the associated clamping plate IT is normally forced in an outward direction away from the associated guide plate l9; pins 2| or any other conventional means are provided for arresting the outward movement of the clamping plate ll by the action of the springs 23.

The guide plates l9 are mounted on the means whereby the clamping devices are maintained in operative relation to the articles being transported by the movable or travelling support over the previously mentioned given or predetermined path. The means referred to is shown in the form of a movable carrier which travels over a path in spaced parallel relation to the aforesaid given or predetermined path. Preferably the movable carrier comprises an endless conveyer one run of which travels in the same direction and in speed synchronism with the one run of the chain I3 and the supporting plates II actuated thereby. The movable carrier consists of a sprocket chain 22 passing over and operated by sprocket wheels 23 mounted in the machine in the manner set forth hereinafter; the sprocket chain 22 is preferably also of the well known roller type and accordingly includes rollers 24 rotatably mounted on the pivot pins whereby the links of the chain 22 are pivotally connected with each other.

As shown in the drawings, the guide plates H! are suitably mounted upon selected links of the chain 22 and preferably are equally spaced apart thereon; the arrangement is such that the clamping devices, that is the clamping plates 1'! thereof are located in spaced opposed registry with predetermined supporting plates H throughout the travel of the two parallel runs of the chains l 3 and 22 over the given or predetermined path and parallel path respectively.

To enable the machine to accommodate articles of different dimensions, the sprocket wheels 23 or their equivalent are carried by bearing boxes 25 slidably mounted in guide brackets 26 mounted on the frame Ill in any convenient manner for instance as shown in Figs. 1 and 1*. Any suitable means may be provided for adjusting the bearing boxes 25 relativelyto the brackets 25 to thereby shift the sprocket wheels 23 and chain 22 with the clamping devices carried thereby in directions toward and away from the supporting plates ll; obviously with the aforesaid adjustments, the distance between the supporting plates II and the co-operating clamping plates I! may be selectively varied to properly accommodate articles of different dimensions and to efficiently clamp the same in place on said supporting plates II.

For the purpose of illustrating the adjusting means referred to above, the bearing boxes 25 are rigidly connected with screwthreaded spindles 21 which project through and are in threaded engagement with internally threaded worm gears 28. The latter are mounted on the frame H3 in any conventional manner so as to be rotatable about their axes without however being capable of any other movement relatively to said frame It. The worm gears 28 mesh with and are rotatably operated by worm pinions 29 fixed upon a common shaft 30 which is journaled in conventional bearings 3| on the frame Ill; the opposite ends of the shaft 30 may be formed with angular heads 32 for the accommodation of an operating crank 33 or said shaft 30 may be rotated in any other conventional manner.

The machine further includes spaced parallel chain rails 34 extending between and connected with the bearing boxes 25, for instance by being bolted to lugs 35 with which said bearing boxes 25 are provided, as shown in Figs. 1 and 1 the chain rails 34 are located one above the other and are traversed by the rollers 24 of the chain 22. In addition, guiding means is provided for maintaining the clamping devices in their intended path without interference with the clamplng action of the clamping plates IT or their equivalent. This guiding means, as shown, consists of guide rails 36 located in. spaced parallel relation to the lower chain rail 34 upon opposite sides thereof and secured in place on said rail, in any convenient manner as by bolts 31 and spacing washers 38 and 38*; the guide rails 36 are provided with guide channels 39 located in opposed registry for the accommodation of the guide plates H as shown in Fig. 2.

In the operation of the illustrated machine, the chains 13 and 22 are intermittently operated by means of any conventional means adapted for the purpose; as such operating means is well known in many forms, it has been deemed unnecessary to illustrate an example thereof. Under such conditions, the articles, which are exemplified by the bottles A in the drawings, are advanced in successive steps over the aforesaid given or predetermined path, each advance being followed by a period of rest during which articles A may be placed in position on and removed from the movable or travelling support. and during which operations for which the machine is designed, such as the application of labels to the articles A, may be performed.

To facilitate the placing of the articles A upon and removal from the movable or travelling support. and to enable other operations referred to in detail hereinafter to be readily carried out, it is desirable to provide the machine with means whereby the clam ing devices. exemplified by the clamping plates IT, are released or periodically adjusted to inoperative positions; in the preferred arrangement the clamping devices are brought into operative association with the releasing means automatically and the latter itself is automatic in action.

The illustrated releasing means includes releasing members 4!! slidably mounted in slide brackets 4| fastened on the guide rails 36 in opposed registering pairs, said members 40 being provided with inwardly directed recesses or seats 42 normally located in the path of travel of the ribs I! of the clamping plates I! when the latter are in clamping position upon an article A as illustrated in Fig. '2. In practice, releasing members 40 are located at predetermined points of the aforesaid given or predetermined path traversed by the articlesAduring transport by the movable or travelling support exemplified by the supporting plates H and associated elements; when the articles are transported in successive steps, the releasing member '40 will be so located that the ribs ll of the clamping plates ll will be positioned in recesses or seats 42* of said releasing members 40--'during periodsof rest between the intermittentimovements of the movable or travelling support. In Figs. 1 and 1a of the drawings, one pair ofco-operating releasing'members 40 is located: at what-may,-for convenience, be termed the inserting station E of the machine, while another pair of cooperating releasing members 44 may be located at the so-called removal station C of said machine.

The releasing members 40 of each co-operating pair are designed to move or be operated in unison and accordingly may be connected at their upper ends by means of a pin 43 as shown in Fig. 2. In the illustrated machine. the releasing members 40- are-automatically operated by suitable means or mechanism in operative synchronism with the associated elements of the machine. The operating means ormechanism. as shown. comprises levers 44 carried by rock shafts 45 and. having forked ends 46 connected with: the pins 43 which preferably are provided with reduced portions 41 forming annular recesses for the accommodation of said forked ends 46 as shown in Fig. 2. The rock shafts 45 are journaled in bearings 48 carried by brackets 49 which constitute integral parts of the spacing washers 38 and are fastened by bolts 50 or the like, to the upper chain rail 34. as illustrated in Fig. 2. Actuating levers 5| are also fixed upon the rock shafts 45 and are provided at their free ends with rollers 52 located in grooves 53 extending lengthwise of operating members 54 and 54 which are respectively carried by slides 55 and 55 arranged for reciprocation in bearings 56 suitably mounted on the frame In. The operating members 54 and 54 are designed to move in unison andaccordingly may be connected by means of a connecting rod 51 or its equivalent, as shown in Fi s. 1 and 1 The reciprocation of the slides 55 and 55 and the corresponding actuation of the operating members 54 and 54 may be. effected through the medium of any suitable operating means. The latter. as shown in Fig. 1 includes a bell-crank lever 58 pivoted at 59 upon a supporting bracket 60 and having its one arm pivotally connected at El with one end of a link 62, the other end of which is in swivelled connection at 63 with a forked member 64 projecting from the operating member 5 The free end of the other arm of the bell-crank lever 58 is forked at 65 for swivelled connection at 65 with an operating rod 61. The latter is controlled and operated by a suitable cam in a manner to periodically rock the bell-crank lever 58 on its pivot 59 to thereby reciprocate the slides 55 and 55 and. with them the operating members 54 and 54 in predetermined timed relation with the cooperating elements of the machine for the purpose of operatively controlling the releasing devices in a manner to be more fully described hereinafter; as the cam which controls and operates the rod 61 may be of conventional type, it has not been deemed necessary to illustrate the same in the drawings.

In many types of machines with which the novel. features hereinbefore set forth may be combined, it is desirable and even necessary to have the articles A properly positioned on the movable or travelling support in order that predetermined operations relating to said articles may be properly and accurately performed. This is exemplified in labeling machines by the application of labels to articles A of cross-sectional form other than circular, such as for instance bottles having a triangular shape in cross-section. Bottles of this type must occupy a position on the movable or travelling support in which the bodies of said bottles are properly registered with or otherwise set relatively to the label applying means in order that the labels may be applied thereto in the intended manner. The illustrated machine accordingly includes setting mechanism located at a point of the path traversed by the articles A which, for convenience of description, is designated hereinafter as the registering station D.

In order that the clamping plates Il may be properly controlled in operative synchronism with the setting mechanism at the registering station D, the illustrated machine includes releasing members 40 corresponding to the previously described releasing members 40' and likewise slidably mounted, in co-operating pairs, in slide brackets M fastened on the guide rails 36; the releasing members 48* are provided with recesses or seats similar to the previously mentioned seats 42 and likewise designed to accommodate the ribs ll of the clamping plates I! when the latter reach and are temporarily at rest at the registering station D. The co-opera-ting releasing members 49 are connected to move in unison by a cross-pin 43 which is engaged by the forked end 46 of a lever 44 carried by a rock shaft 45 journaled on a bracket 49 corresponding to the brackets 49 and also fastened to the chain rails 34. The rock shaft 45 also carries an actuating lever 5H which is connected by means of a link 68 with the actuating lever 5| located, for instance at the inserting station A, so as to move in unison therewith under the operative control of the operating member 54.

The setting mechanism located at the registering station D includes a stationary stop 69 suitably mounted for instance upon the member l2 in predetermined operative relation to the releasing member 40 and to the supporting plates II on which the articles A are transported over the previously mentioned given or predetermined path; to enable replacement and substitution, the stop 69 may be removably fastened in place as by screws 18 or the like. A movable setting member I! is arranged to be reciprocated in operative relation to the stop 69 and, as shown, is carried by a plate 12 adjustably mounted upon a slide '13; to provide for the adjustability of the setting member H, and at the same time to enable the latter to be replaced at will, the plate 12 may be formed with a slot 14 for accommodating a set screw 15 or similar fastening means.

As shown in Fig. 3, the slide 73 is slidably mounted in a slide bracket 16 suitably carried by the member I2 and preferably having a removable plate 11 to facilitate assembling and disassembling of the parts; in practice, the plate 11 is slotted as at Il to receive a lug 18 projecting from the slide 13 and permit movement of said lug 18 in a manner to avoid interference with the reciprocation of the slide 13. Any suitthe label applying means.

able means may be provided for operating the setting member 1! in predetermined operative synchronism with the associated mechanisms. For instance, as illustrated in Fig. 3, a rod 19 may be pivotally connected at with the lug 18 and in swivelled connection at 8| with a lever 82, the rod 19 preferably being screwthreaded for the reception of a nut 83 for the purpose of selectively varying the distance between the connections and 8| to enable necessary or desirable adjustments to be readily made.

The lever 82 is fixed upon a rock shaft 84 journaled in a bearing forming part of a bracket 85 suitably fastened in place upon a portion 86 of the frame It. The rock shaft 84 also carries an arm 8'! which is pivotally connected by means of a link 88 with one arm of a bell-crank lever 89 pivotally mounted at 90 upon a convenient portion of the frame If). The other arm of the bell-crank lever 89 is operatively acted upon by a cam of conventional type in a manner to rock the shaft 84 with the lever 82 and thereby develop the intended reciprocation of the slide 13 and corresponding movements of the setting member H. As the cam controlling the operation of the bell-crank lever 89 may be of conventional form, it has not been deemed necessary to illustrate the same. To facilitate the action of the parts and to cause the setting member H to exert a resilient pressure upon the articles A, in the operation of setting the same in position on the supporting plates II, a tension spring 9| has its one end connected with a projection 92 located at the one end of the link 88, the other end of said spring 91 being fastened to any convenient part of the frame I0.

In the illustrated example, the articles A comprise bottles of triangular shape and cross-section to the one flat side of which labels are to be applied by the machine. In order that the aforesaid fiat side may be accurately located in proper registry with the label applying means, the setting member H is recessed to fit over two diverging sides of the bottle A, and the stop 69 is formed with a flat surface for engagement by the flat surface of said bottle A which is to be labeled as shown in Fig. 4. In practice, the stop 69 is located in a position with its flat surface defining an accurate registering relationship with It will be understood that the setting member 1| and the co-operating surface of the stop 69 will always be designed for co-operation with predetermined articles A in such a manner that when the articles have passed beyond the setting station D, said articles will occupy an accurate position on the plates II or their equivalent predetermined by the operations to which said articles A are to be subjected.

In describing the operation of the illustrated machine, it will be assumed that the chains l3 and 22 are intermittently actuated in synchronism so as to advance the opposed parallel runs of said chains in successive steps of predetermined extent followed by successive dwell or rest periods of predetermined duration.

Under such conditions, the guide plates 19 of the clamping devices will successively enter the guide channels 39 and will be moved lengthwise thereof in the operation of the machine, to maintain the associated clamping plates I! in proper operative relation to the given or predetermined path over which the articles A are transported by the plates ll. As the intermittent operation of the mechanism proceeds, the ribs I'l of a clamping plate I I will, during a rest period of the chains I3 and 22, be located in the seats or recesses 42 of the releasing members 40 located at the inserting station B so that at this stage the particular clamping plate I! at said station B and the releasing members 40 thereat will be in coupled connection with each other.' At the same time, the clamping plates I! located at the stations C and D at the time will be coupled to the releasing members 40 at the last-named stations in a similar manner. During the aforesaid dwell or rest period the operating rod 61 will be actuated by its associated cam in a downward direction in Fig. 1 to thereby swing the bell-crank lever 58 on its pivot 59 in a manner to develop a pushing force upon the link 62 whereby the operating member 54 will be correspondingly shifted toward the left in Fig. 1. This movement of the operating member 54 will be communicated by the rod 51 to the operating member 54 at the opposite end of the machine. This movement of the operating members 54 and 54 will rock the actuating levers 5| and their shafts 45 in a direction to move the levers 44 upwardly and cause said levers to exert a lifting action upon the pins 43 whereby the clamping plates I1 are shifted to inoperative or releasing positions against the tension of the associated springs 20. At this stage, an article or specifically a bottle A may readily be placed upon that plate II which is located at the station B, it beingunderstood that subsequent to this operation, the operating rod 51 will be raised by its cam to operatethe associated parts in a-reverse direction and to thereby shift the operating member 54 to the right in Fig. 1 whereby the lever 5|, rock shaft 45, and levers 44 will be operated in a direction to move the releasing members 40 downwardly and to permit the clamping plate I! to 'yieldingly engage the top of the bottle A which is thereby clamped in position upon the associated supporting plate II. V

As the described operations take place at the inserting station B, the releasing members 40 located at the removal station 0 will be correspondingly operated to similarly control the clamping plate I! which happens to be located at said station C at the time, and to thereby enable an article A which has been labeled or otherwise acted onvby the particular machine to be easily removed from the co-operating supporting plate H. 1 v a a It will be understood as soon as one of the bottles A or equivalent article has been clamped in place on the associated plate H at the station B, that the intermittent advance of the chains I3 and 22 is resumed to transport said bottle A or other article one step forward along the previously mentioned given or predetermined path. At the same time the ribs I! of the next succeeding clamping plate II will be brought into coupling or associated relation with the releasing members 40 at the inserting station B whereupon the previously described operations will be repeated to permit the insertion and clamping of a second bottle A or other article upon one of the supporting plates II. a

As the intermittent advance of the articles or bottles A continues, said articles will at one stage of the transporting operation reach the setting station D and temporarily remain thereat, At this stage, the ribs I! of the co-operating clamping plate I! which is functioning at the time will be in coupled connection with the releasing members 4D which are lifted coincidentally with the releasing members 40 at the inserting sta-' tion B, by the operation of the levers 44 and 5i through the medium of the link 68 which is connected with the lever 5| located for instance at said station B. As soon as the clamping plate I! at the setting station D has thus been shifted to an inoperative position, the bell-crank lever 89 will be operated by its controlling cam to rock the arm 81, rock shaft 84, and lever 82 in a direction to shift the slide 13 toward the right in Fig. 3 and to correspondingly move the setting member ll toward the stop 69. If, at this stage, a bottle or other article A is in registry with the stop 69 and with the path of movement of the setting member H, the latter will engage said bottle or other article A and will force the same against said stop 69 to thereby accurately adjust the position of said bottle or other article A upon the particular supporting plate II by which said article or bottle is carried. At the same time the mechanism is actuated in properly timed relationship to permit the clamping plate I! to return into clamping engagement with said bottle or other article A which accordingly is securely clamped in its adjusted position upon the particular supporting plate H. As the intermittent advance of the chains l3 and 22 continues, the bottle A or other article in the position to which it has been set will be advanced or transported over the given or predetermined path and at the proper stage in the operations will be acted upon for instance by having a label applied thereto by the labeling means of the machine. The labeled article or bottle A, or an article or bottle which has otherwise been acted upon by the machine, will then continue to be transported in successive steps and finally will reach the so-called removal station C and be temporarily released from the clamping action of the particular clamping plate l'l' so as to be capable of being readily removed from the machine.

It will be understood that the bottle or other articles A may be inserted into the machine at the inserting station B and removed herefrom at the removal station C, either manually or antomatically, by suitable mechanisms which may be of any well known and conventional type.

It will be noted, as the bottles or other articles A are transported by the plates l i, that the latter are supported from below by the member I2 and therefore are incapable of yielding either under the weight of the bottles or other articles A, or under the influence of the clamping devices exemplified by the plates IT; in other words, the bottles or other articles A are securely clamped in position on the movable or travelling support during transporting thereof over the previously mentione given or predetermined path.

By rotating the shaft 38 through the medium of the crank 33 or its equivalent, the worm gears 28 may be rotated and because of their screwthreaded connection with the spindles 21, will move the same relatively to the brackets 26 to correspondingly adjust the bearing boxes 25 and thereby selectively shift the sprocket wheels 23 and chain 22 with the associated mechanisms in directions toward and away from the member I2 and the supporting plates ll movably supported thereby; during this shifting of the parts, the rollers 52 of the levers 5| will be shifted lengthwise of the grooves 53 so as to remain in operative connection with the operating members 54 and 54 at all times. With the aforesaid arrangements, it is possible to selectively vary the distance between the lower run of the carrier chain 22 and the supporting plates ll upon the member i2 and to correspondingly vary the relationship of the clamping plates I! to the supporting plates II; it is thus possible to readily adjust the mechanism for accommodating articles A of different dimensions within the range of adjustment of the parts.

The novel mechanisms provide simple and effective means whereby articles to be labeled or otherwise mechanically acted upon are securely and firmly held in position while being transported over a predetermined operative path; the mechanisms in question also provide for the positioning of the transported articles in accurate predetermined relation to an associated portion of the machine to guarantee the accurate performance of operations for which the particular machine is designed.

Various changes in the specific forms shown and described may be made within the scope of the claim without departing from the spirit of the invention.

We claim:

The combination of a travelling support for conveying articles over a predetermined path, an endless carrier one run of which travels in spaced parallel relation to said support and in synchronism therewith, guide rails in spaced parallel relation to said one run of said carrier upon opposite sides thereof, said guide rails having oppositely disposed guide channels extending lengthwise thereof, guide plates fixed upon said carrier at spaced points and arranged to project into said guide channels and to be moved lengthwise thereof by said one run of said carrier. spring controlled clamping plates yieldingly mounted on said guide plates for clamping said articles on said support, ribs extending lengthwise of said clamping plates along opposite sides thereof, releasing members slidably mounted in co-operating pairs at spaced points of said predetermined path and provided with oppositely disposed recesses for the reception of said ribs when said clamping plates arrive at said spaced points whereby said releasing members and said clamping plates are coupled together, and means for s'lidably operating all of said releasing members to concurrently shift the clamping plates coupled therewith relatively to said guide plates to inoperative positions.

GEORGE W. VON HOFE. FRANZ J. HAMMER. 

